Fluoroalkyl ketal esters



United States Patent 3,361,787 FLUOROALKYL KETAL ESTERS Robert A. Braun, Newark, Del., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware No Drawing. Filed Mar. 12, 1965, Ser. No. 439,465 9 Claims. (Cl. 260-468) This invention relates to fiuoroalkyl ketal esters. It is more particularly directed to compounds of the formula Where R can be an alkyl radical of 1 through 18 carbon atoms, an alkyl radical of 1 through 18 carbon atoms substituted with chlorine or fluorine, an alkenyl radical of 2 through 6 carbon atoms, a cycloalkyl radical of 3 through 7 carbon atoms, phenyl, or phenyl substituted with chlorine, bromine, fluorine, methoxy, alkyl of 1 through carbon atoms, or nitro;

X can be a perfiuoroalkyl radical or a monochloroperfiuoroalkyl radical, both of 1 through 5 carbon atoms; and

Y can be a perfluoroalkyl radical of 1 through 5 carbon atoms.

The compounds of the invention are thermally stable liquids which are water insoluble, non-flammable and hydrolysis resistant. The compounds are also liquid over a wide temperature range. These properties make the compounds useful as hydraulic fluids, heat transfer agents and as buoyancy and damping fluids in measuring and recording instruments.

The compounds of the invention can be prepared by the thermal rearrangement of perhaloalkyl substituted The cyclic acetal starting material can be prepared by the reaction of a perhaloketone with an alkyl orthoformate. This reaction is described in more detail in copending application Ser. No. 325,468, filed Nov. 21, 1963.

3,361,787 Patented Jan. 2, 1958 In this equation R, X and Y are defined as in Formula 1.

The liquid cyclic acetal starting material is placed in a bomb or open container and heated to a temperature of from 160 C. to 300 C. Completion of the thermal rearrangement is best determined by periodic sampling and infra-red analysis. When the carbonyl (C=O) band values show no further increase, the reaction is substantially complete. This, in the usual case, takes from 6 to hours. The product can be separated from unreacted starting material by gas chromatography or fractional distillation.

The compound produced in this fashion Will be substantially pure, but if further purification is necessary or desirable, this can also be accomplished through gas chromatography or fractional distillation.

The following examples are presented so that the invention will be more easily understood and readily practicedi These examples are intended to be illustrative, and show only representative embodiments of the invention. Those compounds not specifically disclosed can be made by similar methods, varying significantly only in the reactants. In the examples, all parts are by weight.

Example 1 Twenty parts of H360 CF:

were heated in a bomb at -l65 C. for 75 hours to give 12.3 parts of a liquid, which upon separation by preparative gas chromatography, gave 1.2 parts of 0 C|F 0E HaC0C(|3OCO-CH3 CF; CFa

Reactant Product Examp1e5 F F F F (I? ([JF (13F; F F

Q CF; I

F F C F F OF3 CF F F F F (Mm Q F F OFa OF:

(H) (EFF C a Examplefi CHFCHOHZO\ CF: CHFCHCHZOOOO?OCH2CH=CH2 C--O CFa CFa l l\ CH2=CHCH2O 0 0 CF:

O6: C s

And the following reactant can be heated in a bomb at 190 C. for 50 hours to give the corresponding product.

Reactant Product $F2Cl 0313 0 OFzGl (H) (IJFICI Example 7. CaHC(lJO(l)-O C3H1 O H O 0 0 CF: CFa CF:

C CFzCl The claims are: 5. A compound of the formula 1. A compound of the formula 40 0 it t ROC(|3O(i30R Y Y 6. A compound of the formula Where F F 0 CF; CF; F F

R'is selected from the group consisting of alkyl radicals F IB I I F of 1 through 18 carbon atoms, alkyl radicals of 1 I through 18 carbon atoms substituted with a member F F s F of the group consisting of chlorine and fluorine, 7, A compound f th for la alkenyl radicals of 2 through 6 carbon atoms, cyclo- 0 CF CF alkyl radicals of 3 through 7 carbon atoms, phenyl, H a a phenyl substituted with a member of the group con- CHFCH-CHIOCCO-CO-CH2GH=CH sisting of chlorine, bromine, fluorine, methoxy, alkyl Ops of '1 through 5 carbon atoms and nitro; X is selected from the group consisting of perfluoro- A compound of the formula alkyl radicals and monochloropcrfluoroalkyl radif CFa CFa cals, both of 1 through 5 carbon atoms, and H C OJ7CO-COC H Y is a perfiuoroalkyl radical of 1 through 5 carbon F201 CF20 atoms. 2. A compound of the formula 9. A process for the preparation of the compound or 0 CF CF claim 1, said process comprising heating, at autogenous H s a pressure to a temperature of from 160 C. to 300 C., H a compound of the formula CF; OF3

R() X 3. A compound of the formula C 0 CF OF H a a 34/6 Y F CHaCOC-COCOCHzCFa \C/ 4. A compound of the formula 0 OF; CF; where |l l l R is selected from the group consisting of alkyl radicals of 1 through 18 carbon atoms, alkyl radicals of 1 CF; through 18 carbon atoms substituted with a member 5 of the group consisting of chlorine and fluorine, al- Y is a perfluoroalkyl radical of 1 through 5 carbon kenyi radicals of 2 through 6 carbon atoms, cycloatoms. alkyl radicals of 3 through 7 carbon atoms, phenyl References Cited and phenyl substituted with a member of the group UNITED STATES PATENTS consisting of chlorine, bromine, fluorine, methoxy, 5

alkyl of 1 through 5 carbon atoms and nitro; 3,125,599 3/1964 Wamen 260 535 X is selected from the group consisting of perfluoroalkyl radicals and monochloroperfluoroalkyl radicals, LORRAINE WEINBERGER Primary Exammer' both of 1 through 5 carbon atoms, and S. WILLIAMS, Assistant Examiner. 

1. A COMPOUND OF THE FORMULA 